Animation showing an activated dendritic cell (antigen-presenting cell, grey with spiky projections) entering the lymph node (green area) through a draining lymph vessel. Here the dendritic cell presents the antigen material to T cells (rounded grey cells). Specific T cells which recognise the antigen material become activated (glows white and enlarges at activation) and proliferate. Some of the T cells migrate within the lymph node to effector B cells (pink). The activated B cells then proliferate and secrete specific antibodies (Y shaped proteins).